The purpose of the proposed P50 Center, Translational Drug Abuse Prevention (TDAP), is to serve as a national resource for cutting-edge, multidisciplinary, scientifically innovative and synergistic Type I and II translational prevention research in drug abuse that seeds future research, practice, and policy in the child welfare system (CWS). Children and adolescents with involvement in the CWS, and those adopted following CWS involvement, are at greatly elevated risk for drug use, HIV-risk, and associated problems including delinquency and poor mental health. The TDAP Center will extend our previous work on drug abuse prevention and broaden the reach and impact of our basic and intervention work in this area through an integrated program of research spanning Type I and Type II prevention research that will increase our understanding in three key areas that have direct effects on CWS policy and practice: (1) Understanding of underlying mechanisms and processes associated with exposure to high levels of early life adversity, and specific to risky decision-making in certain social contexts that are common for CWS youth during early adolescence; (2) reducing the high rates of drug use and engagement in HIV-risk behaviors in adolescent girls in the CWS via novel preventive intervention strategies; and (3) identifying methods for implementing extant evidence-based interventions into CWS real-world settings with high fidelity and empirically measuring implementation success/failure in the context of a public child welfare system-initiated reform. The above Research Components will be supported by a Methodology and Statistics Core that will facilitate integrated qualitative and quantitative analyses of the incoming data, as well as integrate the new data with our large existing data resource of CWS studies. A Pilot and Training Core will support the development of small-scale studies designed to lead to innovative, new independent research projects led by early career, and minority researchers in the area of prevention of drug abuse and HIV-risk in the CWS. Finally, an Administrative Core will provide leadership within the Center, interface with an external Advisory Board comprised of experts in CWS leaders and policy makers, and facilitate training and mentoring of Early Career Scientists.